Screw.



N0.'86s,183. PATENTED AUG.13,1 90'7.

' W. B. JACKSON s W. BURNBTT.

SCREW. APPLIOATION FILED NOV. 16,1906.

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WILLIAM B. JACKSON AND WILLIAM BURNETT, OF ELLINWOOD, KANSAS.

SCREW.

Specification of Letters Patent.

Patented Aug. 13, 1907.

Appucation ie November 16, 1906, serial No. 343,1762.

To all whom it may concern:

wBe it known that we, WILLIAM B. JACKSON and WIL- LIM BURNn'rT, citizensof the United States, residing at Ellinwood, in the county of Barton and State of Kansas, have invented certain new and useful Improvements in Screws, of which the following is a speciiication.

. The object of our invention is to provide an improved construction of screw in which means are provided to lock the screw in place and prevent its accidental withdra'wal. y

The invention,l consists in certain constructions and arrangements of the parts of the screw adapted to be locked in place, all as will be hereinafter fully described and claimed. A

For a full understanding of the invention and the meritsrthereof and also to aequirea knowledge of the details of .construction of the means for effecting the result, reference is to be-had to the following description and accompanying drawings, in'whicrh:

Figure 1 is a longitudinal sectional view of one form of screw in which the invention may be embodied; and Fig. 2 is a perspective view, partially in section, of another form of screw to which the invention may be applied. f

Corresponding and like parts are referred to in the following description and indicated in all the views to the point where the threads begin, as illustrated in y At the bottom of the longitud-inall bore 3, the body of the screw is formed with transverse -openings 4 extending outwardly in opposite directions from the bore 3; l

the drawings.

5 designates a key which is constructed of metal and is provided with two integrally connected members 5a that are initially in contact with each other throughout their length, the said key being initially of uniform i thicknessvthroughout and beingdesigned te fit in the longitudinal bore 3. In the preferred construction, the key 5 is constructed of a single piece of4 metal doubled upon itself at its middle to form the two members 5, and the endsyof these members are first inserted in the bore 3. Then, after the screw has been screwed into its place, one or two taps upon the head of the key 5 will result in the divergence of the two extremities of the members l5EL in opposite directions out through the transverse openings 4 and into thewood or the like, so as to lock the screw securely in place.

As illustrated in Fig. 2, the screw lB is provided with a head 2 having a transverse kerf or groove 6 for the application of a screw driver. In this construction, the bore and transverse opening are similar to the bore and opening of the first described screw, but the key is initially of such a length that its head will lie within the marginof the bottom ofthe kerf 6, so as to interfere in no wise with the proper use of the 'screw-driver to turn the screw. In order to unlock the screw, it is only necessary to drive the key downwardly until its head reaches the bottom of the bore 3, whereupon the head will split where it connects the two members 5 together and thereby allow the screw to be withdrawn.

From the foregoing description in connection with the accompanying drawing, it will be seen that we have provided a very simple construction of lock screw, in which the key is of uniform diameter throughout in initial construction and may therefore be driven entirely down into the longitudinal bore 3 so as to lock the screw as above described. In the manufacture, these keys may be so made as to accompany each screw, and avoid the necessity of looking around for a key when it is desired to practice the invention. A

Having thus described the invention, what is claimed as new is:

As' a new article of manufacture, the herein described screw provided with a head having a transverse kerf for the ,reception of a screw driver and a longitudinal bore extending downwardly from the kerf and with a transverse opening leading downward in opposite directions from the bottom of the bore, and a key consisting of an integral piece of metal bent at its middle to produce two members fitted within the bore with their extremities lowermostiand diverging and lying wholly within the transverse openings, the opposite end of the said key lying below the bottom wall of the kerf for the purpose set forth.

In testimony whereof we ax our signatures in presence of two witnesses.

lWIL'LIAM nJAeKsoN. [n s] WILLAM BURNETT. [n s.]

Witnesses:

Gno. W. .TAcKsoN, Pnyon BURNn'r'r. 

